Jerusalem: Security forces locked down parts of Jerusalem’s Old City on Saturday and an ultra-sensitive holy site remained closed after an attack that killed two police officers and heightened Israeli-Palestinian tensions.

Three Arab Israeli assailants opened fire on Israeli police on Friday in the Old City before fleeing to the nearby Haram al Sharif, known to Jews as the Temple Mount, where they were shot dead by police.

Israeli authorities said they had come from the flashpoint holy site, which includes the Al Aqsa mosque and the Dome of the Rock, to commit the attack. Israeli authorities took the highly unusual decision to close the Al Aqsa mosque compound for Friday prayers, leading to anger from Muslims and Jordan, the holy site’s custodian. Israeli Prime Minister Benjamin Netanyahu has signalled it is to remain closed until at least Sunday while security was assessed.

He also spoke of increasing security at entrances to the holy site when it reopens — likely to be a controversial move. On Saturday, there was restricted access through Damascus Gate, the main entrance used by Palestinians into Jerusalem’s Old City, with only residents with identification being allowed to pass.

Around 20 Palestinians waited at police barriers near Damascus Gate to see if they would be let through.

“This is not security. This is punishment,” said Bader Jweihan, a 53-year-old accountant for a bus company who was trying to get to work but was refused entrance there.

Musa Abdelmenam Qussam, 73 and with poor eyesight, was being helped by one of his grandsons as he walked with a cane and sought to enter through the police barrier.

The owner of a book wholesale shop in the Old City, he said he usually prays at Al Aqsa every day. “This mosque is not only for Muslims. Tourists come,” he said after being denied entrance.

Jaffa Gate, heavily used by tourists and near the Old City’s Jewish Quarter, was open but with a heavy police presence. A group of tourists from Poland said they were concerned when they heard about the shooting on Friday but wanted to continue their visit. They were on their way to do some shopping in the Old City and visit the nearby Garden of Gethsemane, where Christians believe Jesus prayed the night before his crucifixion.

“It stressed me a little,” said Ewa, who did not want to give her last name or age. At Lions Gate near the site of the attack, police guarded the entrance and restricted access, checking IDs.

The attack and aftermath was one of the most serious incidents in Jerusalem in recent years.

Palestinian president Mahmud Abbas and Netanyahu spoke by phone on Friday as tensions rose in the wake of the incident.

Israeli authorities also detained Jerusalem’s top Muslim cleric, grand mufti Muhammad Ahmad Hussein, as crowds gathered at the gates of the Old City after the attack, his son said.

He was released later on Friday after being questioned, according to another of his sons.

With Al Aqsa closed, crowds gathered at Old City gates and held Friday prayers there.

The mufti had criticised the closure of Al Aqsa before being detained.

“I have very little information about it, but it doesn’t mean you should close the mosque for prayers,” he had told journalists at the Lions Gate entrance to the Old City.

The Haram al-Sharif / Temple Mount is central to the Israeli-Palestinian conflict, with Palestinians fearing Israel may one day seek to assert further control over it.

It lies in east Jerusalem, occupied by Israel in the 1967 Six-Day War and later annexed in a move never recognised by the international community. It is considered the third-holiest site in Islam and the most sacred for Jews. Jews are allowed to visit but not pray there to avoid provoking tensions.

A wave of unrest that broke out in October 2015 has claimed the lives of at least 281 Palestinians or Arab Israelis, 44 Israelis, two Americans, two Jordanians, an Eritrean, a Sudanese and a Briton, according to an AFP toll.